Arnold series were effectively loss leaders - they typically sold for negative margin.
MP neglected to pay Bakery Barn for crunch bars, resulting in lawsuits and counter-claims (claiming that MP received bad product) and MP moving to a new, inferior vendor. Now the band's back together, but the reputational damage is likely permanent.
The launch of the naturals series was a thud.
Protein is a commodity, but MP still wants to treat it as a premium product, resulting in steadily declining sales.
All in all, MP lost whatever momentum it gained by trimming fat, and is now completely rudderless - no real plan for increasing market share, becoming profitable, or producing anything approaching value for its shareholders. The fact that they didn't 8-k the renewed relationship with Bakery Barn (and return to the classic CC bars) tells you all you need to know about MP's focus on driving share price.